Russell Brand is one step closer to severing all ties with Katy Perry -- because he's surrendered his interest in the house they bought together while they were happily married -- if they were ever really happily married.
TMZ got hold of a quitclaim deed that Russell filed in L.A. ... giving Katy all rights to the $6.5 million house -- lock, stock and barrel.
Sources tell us ... it's all part of the property settlement agreement between Russell and Katy.
It's further proof of what Russell said -- that he doesn't want a penny of Katy's money and wants the split to go as amicably as possible ... so far, so good.